The present invention relates generally to applicator systems that are used to spray fluids, such as paint, sealants, coatings, and the like. More particularly, the invention relates to a proportioning cylinder of a pumping subsystem of a spray system.
Some fluid applicators have separate “A-side” and “B-side” fluid systems (e.g. pumps, reservoirs, and fluid lines) that carry different fluids components. These components are isolated until sprayed or otherwise applied, whereupon the components mix and chemically interact to form an application material. Two-component fluid spray systems are commonly used to apply epoxies, foams, and two-component paints. Paint systems, for example, may combine A-side paints with B-side catalyst materials. Common catalyst materials include isocyanates, polyesters, epoxies, and acrylics. Different paints or other A-side materials may require different B-side catalysts.
A- and B-side fluid systems typically comprise separate fluid sources (e.g. reservoirs or lines) that are pumped via separate pumps to a common sprayer head actuated by a human operator or an automated machine process. Required spray pressures vary as a function of material and application, and desired flow rates of A- and B-side fluids often differ. Paints and catalysts intended to be combined in a 10-to-1 ratio, for instance, will necessitate A-side pump displacement ten times greater than B-side pump displacement.
Spray systems use a variety of different pumping mechanisms. Many spray systems utilize gear pumps for continuous pumping fluid flow. Wear over time can cause gear pumps to slip or grind.